Bespoked was once again in Sour’s hometown of Dresden, Germany, a few weeks back. And even though Sour’s mostly steel bikes are already made by hand locally, they decided to really pull out the stops for the world’s largest handmade bike show. A few unique builds and retro MTB inspiration led to some cool custom bikes. But it was really this combination of carbon and steel road bike that stole the Sour show.
Sour Carbon Crush prototype steel & carbon road bike
Off-road bikes are surely Sour’s heart, but with the success of their recent Space Cake road bike, they decided to put some more R&D onto the road. The resulting project is this Carbon Crush, a prototype steel and thermoplastic carbon road bike.
The spark of an idea was to create a more sustainable performance road bike. The steel used to build modern performance bikes already has high recycled material content. But not so much for most carbon in bikes. So, instead of bonding in conventional thermoset resin-bound carbon tubes, Sour worked with a local Dresden company manufacturing carbon-reinforced composite tubing with high recycled carbon fiber content, bound together in a thermoplastic matrix.
The resulting tubes may be incrementally heavier and not quite as stiff as the highest-mod thermoset epoxy resin carbon tubes. But they are fully recyclable, already include recycled content, and are both more impact-resistant and tougher than conventional carbon.
Prototype sustainable carbon + steel construction
The Carbon Crush started with the same butted 4130 construction of their Space Cake. It then had its seat tube literally cut out, and the large headtube window manually machined out of the already-welded frame.
The thermoplastic carbon tubes were made just around the corner from Sour’s workshop, where everything was bonded together in-house. Sour is proud to say that every bit of the process was engineered and manufactured in Dresden, giving a quick shoutout to ActoFive (also just up the street in the same industrial neighborhood) for their expertise and advice on bonding together bike frames.
Sour made the prototype Carbon Crush just in time for the show – saying the paint and adhesives might not have been fully dry when they rolled it out to show off. But while it started as a proof of concept, and is still very much ‘in development’, Sour says it is a “serious step toward smarter, cleaner” bike building that they will continue to refine for production.
Sour Party Dome steel hardtail inspired by ‘96 Kona Lava Dome
Now for some eye candy. This special Sour Party Dome steel show bike takes its obvious inspiration from the old school cool Kona Lava Dome. The Party Dome is really just Sour’s standard Pasta Party do-it-all bikepacking-ready steel mountain bike hardtail with a fresh retro makeover.
The Lava Dome itself might still be a contemporary bike from Kona, but like Sour owner Christoph Süße, when I hear that name, I’m transported back to a 1990s era mountain bike.
Sour gave their Party Dome a pretty sweet build to match its killer looks. The limited edition silver SRAM 1987 Eagle Transmission seems like a perfect match. Then, add in some shiny silver Hope brakes & headset, and a custom-painted Manitou fork for style, plus the uncommon silver dropper post from PNW to top it all off.
But the real highlight of this build is Sour’s over-the-top one-off steel Foolseye crankset. Created as a ‘tribute’ to the wild experimental early days of 90s mountain bikes, Sour wanted to create a modern version of the classic Bullseye cranks.
So, Sour bent up a bunch of steel plate, machined-in their new name, welded it all together, and did a bunch of grinding to smooth it all out. Fellow Saxony Cycling fabricator Cyber Cycles, who makes their own tubular steel crankset, helped out with the CNC-machined integrated 24mm spindle & spline interface. Plus, they get a 3-bolt SRAM chainring mount.
Sour admits that the Foolseye cranks are “a bit on the heavy side” at a claimed 722g before you add a chainring. But they are open to building more of them, or maybe even refining them, if there is interest.
Chime in on Sour’s Instagram if you want to encourage their foolish endeavors.
Sour Steel P.P. modern hardtail inspired by 90s Yeti Easton A.R.C.
The Sour P.P. is another modern steel hardtail inspired by 90s mountain bikes, this time in a collaboration with Hunt wheels to celebrate their recent 10th anniversary.
Just like Yeti bragged in big letters on its downtube of the butted & tapered Easton aluminum tubes that made up its 1992 Alloy Racing Composite frame – Easton Yeti A.R.C. Sour reproduced the same style for its retro-modern hardtail – maybe made funnier for all of us immature juvenile minds out here reading the name P.P.
So the butted 4130 chromoly Pasta Party becomes Steel Sour P.P. in the same turquoise and gray.
It gets a new Shimano XTR Di2 groupset and, of course, some sweet carbon Hunt Proven XC mountain bike wheels wrapped in Terravail tanwall tires. They even managed to build it up with the same purple anodized highlights for the seatpost and bar ends, and grippy rubber brake lever covers.
#chefskiss
Saxony Bike: a Sour Purple Haze with locally made components
To finish things off, dubbed ‘The Saxony Bike,‘ this custom spec’d Sour Purple Haze is a project of the Cycling Saxony collective of bike industry companies based in the region around where Bespoked is held in Dresden, Germany. There’s a surprisingly large number of cycling companies, both small & large, in the region, many owned by young creative entrepreneurs
The real highlight of this bike for me, though, was that Timba watermelon frame bag. The Dresden custom bikepacking bag maker’s specialty is often making a whole set of bags with matching colors & stripes that line up from one bag to the next. But this simple single red bag with seeds just looks perfect against the rind-green of the frame.
I’d still call this dropbar adventure gravel bike an almost mountain bike, if only on account of the massive for gravel 29×2.25″ Schwalbe Rick XC MTB tires.
In addition to the locally-welded and painted Sour. There’s also the locally made ActoFive crankset, and super fast-engaging Qvist hubs, which Qvist laces to carbon rims just outside of Dresden.
